PLC控制在转炉上的应用案例

介绍荣信钢铁转炉过程控制系统的组成、系统功能、技术应用。     

结合变尺度法的改进类电磁机制算法

标准类电磁机制算法处理连续函数优化问题时存在最优参数选取和收敛速度问题.数值实验研究表明类电磁算法不具备初值敏感性,并在搜索后期算法收敛速度缓慢甚至可能出现停滞.数值实验分析指出粒子之间达成动态力平衡状态是造成算法停滞的可能原因之一,提出一种解决策略是摒弃EM算法后期搜索过程,结合变尺度法对EM算法前期搜索到的近似最优值进行二次优化.该混合计算方法将二者的优势相结合,实验结果表明新方法在保证计算实时性的同时,取得了较高的计算精度.最后,对EM算法本身构造提出一些改进意见,并初步建立用于连续函数优化的EM算法计算框架,为后续更深入的研究EM算法提供参考.     

Solving single-product economic lot-sizing problem with non-increasing setup cost,constant capacity and convex inventory cost in O(N log N) time

This paper considers an economic lot sizing model with constant capacity, non-increasing setup cost, and convex inventory cost function. Algorithms with computational time of O(N×TD_N)have been developed for solving the model, where N is the number of planning periods and TD_N is the total demand. This study partially characterizes the optimal planning structure of the model. A new efficient algorithm with computational time of O(N log N) has also been developed based on the partial optimal structure. Moreover, computational study demonstrates that the new algorithm is efficient.     

使用动作脚本设计互动媒体

使用Flash制作动作,如果只基于时间轴和动画图层来设计,将会受到很大的限制,例如一些复杂、精彩的动画效果难以实现,也不能让观赏者与媒体互动,即媒体不具有交互性。要想动画具有交互性,能使观赏者通过选择来控制播放的顺序或呈现不同的内容,就需要使用Flash的动作脚本语言。     

抗噪Roberts算子边沿检测器

图像边缘检测是图像分割、目标识别、区域形态提取等图像分析技术的基础。边沿检测的软件实现有很多方法,但其一般无法保证在低成本计算平台上的实时性。因此文中基于形态学滤波和Roberts边沿检测算法提出一组数字电路,用以实现低成本、实时图像边沿检测器。文中还对比了Roberts算子的Matlab上实现和硬件实现的实际效果,发现实际硬件的边沿检测精度更高,噪声更多,必须采用去噪电路。该检测器消耗ALTERA-EP4CE115中2139个逻辑单元,每秒可处理30帧分辨率为640*480的RGB图像。     

微气体传感器测试系统的恒流配气系统研究

针对恒流混合气体在微气体传感器实验中的重要性,根据道尔顿分压定律和阿马伽定律,采用质量比动态配气法,实现了实验用恒流配气系统.基于NI USB6215系列多功能数据采集卡,以LabVIEW8.5为软件开发平台,设计了恒流配气系统软件控制界面.通过计算机严格控制MFCs流量调节,配比出不同浓度氢气混合气体.气体流量始终保持在1L/min,上下波动不超过10mL/min.分析了气体流量值出现波动的原因,为进一步完善恒流配气系统提供了参考.     

基于WCF的分布式应用开发

本文介绍了Microsoft用于建立和运行面向服务的应用程序的统一框架WCF的系统结构和技术要素,分析了WCF用于分布式开发的优点及项目的多层开发技术,并通过开发具体分布式应用程序来展现基于WCF构架的分布式应用程序的编程步骤与技巧。     

ProxyServer中Cache的管理和使用

使用Ｃａｃｈｅ可以减少Ｂｒｏｗｅｒ的等待时间和降低代理服务器和Ｉｎｔｅｒｎｅｔ的通信量,本文主要介绍了Ｐｒｏｘｙ对Ｃａｃｈｅ管理和使用。     

Wave–current interaction with a vertical square cylinder at different Reynolds numbers

Railway Engineering Science - Large eddy simulation is performed to study three-dimensional wave–current interaction with a square cylinder at different Reynolds numbers, ranging from 1,000...     

Buckling of carbon fiber composite pyramidal truss core sandwich columns

This paper deals with the theoretical prediction of global buckling loads for carbon fiber composite pyramidal truss core sandwich columns. Different from thin plate structures, transverse shear effect can not be neglected for sandwich structures. In addition, the attributes of the laminated face sheets are considered in the present paper. A zig-zag displacement approximation is made. Based on the principle of minimum potential energy, equilibrium equations and boundary conditions are derived via the variational method. The critical buckling loads under various boundary conditions are presented. In order to validate the reasonableness of the equivalent-core method, the strain energies stored in the actual discrete truss members and the equivalent continuous homogenous core layer are calculated respectively and compared, and a good agreement is obtained. The proposed analytical method is verified by comparing with the published theoretical predictions and experimental results.